The invention discloses a nonaqueous electrolytic solution, a preparation method thereof and an application in a lithium ion battery. The non-aqueous electrolytic solution comprises lithium salt, organic solvent and additive, and described organic solvent comprises chain carbonate, cyclic carbonate, silane-substituted cyclic carbonate and fluorine-containing ether diluent; Said additive comprises lithium difluorophosphate , cyclic sulfate, tris(2,2,2-trifluoroethyl) phosphate. The lithium-ion battery prepared by the non-aqueous electrolyte of the present invention can improve the fast charging rate performance and cycle performance on the basis of maintaining a conductivity of more than 8.5 mS / cm, and the capacity retention rate after 500 cycles can still be 92% at the same time. % or more, it has excellent battery fast charging performance and cycle performance, and the self-extinguishing time is below 2s / g, with excellent flame retardancy, which can further improve the safety performance of lithium-ion batteries and can be widely used in lithium-ion batteries. battery.